What does inversely and directly proportional mean?

Inversely proportional means that one variable goes up while the other goes down. Directly proportional means that both variables increase or decrease at the same time. ex: The volume of a gas at constant pressure is inversely proportional to gas pressure, thus this means that as pressure increases, the volume of the gas will decrease. ex: The volume of a fixed amount of gas is directly proportional to absolute pressure, thus this means that when you heat a gas the volume also increases.